NCAM140 and pCREB Expression after Tianeptine Treatment of SH-SY5Y Cells

OBJECTIVE: Antidepressants Modulate Neuronal Plasticity. Tianeptine, An Atypical Antidepressant, Might Be Involved In The Restoration Of Neuronal Plasticity; It Primarily Enhances The Synaptic Reuptake Of Serotonin. Ncam140 Is Involved In Neuronal Development Processes, Synaptogenesis And Synaptic Plasticity. We Investigated The Effect Of Tianeptine On The Expression Of Ncam140 And Its Downstream Signaling Molecule In The Human Neuroblastoma Cell Line Sh-sy5y. METHODS: NCAM protein expression was measured in human neuroblastoma SH-SY5Y cells that were cultivated in serum-free media and treated with 0, 10, or 20 microM tianeptine for 6, 24, or 72 hours. NCAM140 expression in the tianeptine treatment group was confirmed by Western blot, and quantified through measurement of band intensity by absorbance. CREB and pCREB expression was identified after treatment with 20 microM tianeptine for 6, 24, and 72 hours by Western blot. RESULTS: Compared to cells treated for 6 hours, cells treated with 0 or 10 microM tianeptine for 72 hours showed a significant increase in NCAM140 expression and cells treated with 20 microM tianeptine showed a significant increase after 24 and 72 hours. The pCREB level in cells treated with 20 microM tianeptine increased in time-dependent manner. CONCLUSION: Our findings indicated that the tianeptine antidepressant effect may occur by induction of NCAM140 expression and CREB phosphorylation.

Fluoxetine Increases the Expression of NCAM140 and pCREB in Rat C6 Glioma Cells

OBJECTIVE: Dysfunction of neural plasticity in the brain is known to alter neural networks, resulting in depression. To understand how fluoxetine regulates molecules involved in neural plasticity, the expression levels of NCAM, NCAM140, CREB and pCREB, in rat C6 glioma cells after fluoxetine treatment were examined. METHODS: C6 cells were cultured after 20 min or after 6, 24 or 72 h treatments with 10 microM fluoxetine. Immunocytochemistry was used to determine the effect of fluoxetine on the expression of NCAM. Western blot analysis was used to measure the expression levels of NCAM140 and CREB and the induction of pCREB after fluoxetine treatment. RESULTS: NCAM expression following 72-h fluoxetine treatment was significantly increased around cell membranes compared to control cells. Cells treated with fluoxetine for 6 and 72 h showed a significant increase in NCAM140 expression compared to cells treated for 20 min. The level of pCREB in the cells treated with fluoxetine for 72 h not only increased more than 60%, but was also significantly different when compared with the other treatment times. The 72-h fluoxetine treatment led to the increase of NCAM140 and the phosphorylation of CREB in C6 cells. CONCLUSION: Our findings indicate that fluoxetine treatment regulates neuronal plasticity and neurite outgrowth by phosphorylating and activating CREB via the NCAM140 homophilic interaction-induced activation of the Ras-MAPK pathway.

Chronic Treatment of Fluoxetine Increases Expression of NCAM140 in the Rat Hippocampus

OBJECTIVES: Most of the mechanisms reported for antidepressant drugs are the enhancement of neurite outgrowth and neuronal survival in the rat hippocampus. Neural cell adhesion molecule 140(NCAM140) has been implicated as having a role in cell-cell adhesion, neurite outgrowth, and synaptic plasticity. In this report, we have performed to elucidate a correlation among chronic antidepressant treatments, NCAM140 expression, and activation of phosphorylated cyclicAMP responsive element binding protein(pCREB) which is a downstream molecule of NCAM140-mediated intracellular signaling pathway in the rat hippocampus. METHODS: Fluoxetine(10mg/kg) was injected acutely(daily injection for 5days) or chronically(daily injection for 14days) in adult rats. RNA and protein were extracted from the rat hippocampus, respectively. Real-time RTPCR was performed to analyze the expression pattern of NCAM140 gene and western blot analyses for the activation of the phosphorylation ratio of CREB. RESULTS: Chronic fluoxetine treatments increased NCAM140 expression 1.3 times higher than control in rat hippocampus. pCREB immunoreactivity in the rat hippocampus with chronic fluoxetine treatment was increased 4.0 times higher than that of control. CONCLUSION: Chronic fluoxetine treatment increased NCAM140 expression and pCREB activity in the rat hippo-campus. Our data suggest that NCAM140 and pCREB may play a role in the clinical efficacy of antidepressants promoting the neurite outgrowth and neuronal survival.

Characterization of Differentially Expressed Genes upon Chronic Fluoxetine Treatment in Rat C6 Glioma Cells / 대한정신약물학회지

OBJECTIVE: The aim of this study was to identify diffrentially regulated genes after the treatment of fluoxetine in rat C6 glioma cells using cDNA microarray chip techniques and real-time RT-PCR. METHODS: Cells were incubated for 24 hours, and for 72 hours with or without 10 uM fluoxetine. Total RNAs extracted from cells were reversely transcribed to cDNA. These cDNA were used to carry out cDNA microarray chip. A part of the up-/down-regulated genes in cDNA microarray result were confirmed by real-time RT-PCR. RESULTS: 1) Genes in fluoxetinetreated cells for 72 hours (chronic treatment) were more regulated than that in fluoxetine-treated cells for 24 hours (acute treatment). 2) The expression level of Gs gene in fluoxetine-treated cells for 24 hours hardly altered, but that of Gs in fluoxetine-treated cells for 72 hours significantly increased. The expression of Gi2 also decreased in 72 hours in relation to 24 hours after the administration of fluoxetine. 3) The expression level of NCAM140 gene in fluoxetine-treated cells was higher than that in control cells. CONCLUSION: We identified genes (Gs, Gi2 and NCAM140) related to neural plasticity and intracellular signal transduction cascade from our result. This implies that fluoxetine may inhibit atrophy or death of impaired neural cells by promoting neurite outgrowth.